Chocolate Roses - Help Please!

Hi I wonder if anyone can offer some advice please. This is my first time doing a chocolate roses cake. I am making the chocolate roses myself. I want to know please how to store them before attaching them to the cake as they seem v. soft! also how to attach them to a chocolate fondant cake as there is ribbon going round the base of each cake too and the roses are to cascade down the front and also where should I store this cake before delivery. I'm worried about them wilting or breaking off as they are quite heavy once made up. Should the backs be fairly flat for attaching to the cake?

Sorry lots of questions I know but first time working with this chocolate modelling paste.